1) Field of the Invention
The present invention relates to a starting device for an internal combustion engine. More specifically, the present invention relates to deciding whether to provide the internal combustion engine with assistance using a starter.
2) Description of the Related Art
A typical cylinder injection type internal combustion engine (hereinafter, “engine”) has cylinders with combustion chambers. To start the engine, which is at rest, fuel is injected and ignited into the combustion chamber of a cylinder in an expansion stroke (hereinafter, “expansion-stroke-cylinder”). The fuel burns and produces combustion energy. The combustion energy is used to obtain the power to start the engine. However, the combustion energy alone is sometimes insufficient to start the engine. Various solutions have been proposed to solve this problem.
Japanese Patent Application Laid Open No. 2002-4985 discloses a conventional starter device. In the conventional technology, when the engine is at rest, an expansion-stroke-cylinder is detected, and fuel is injected and ignited into the expansion-stroke-cylinder. Moreover, if the engine does not start because of insufficient combustion energy, a motor is used to assist the cranking to reliably start the engine.
Japanese Patent Application Laid Open No. 2002-39038 and Japanese Patent Application Laid Open No. 2002-4929 disclose other conventional technologies.
Thus, conventionally, the fuel is injected and ignited into the expansion-stroke-cylinder, and it is determined whether the engine is going to start properly, and if the engine is not going to start, a starter is used to assist the starting of the engine. In other words, whether to use the starter is decided after confirming that the engine is not going start.
However, because whether to use the starter is decided after confirming that the engine is not going to star, a time lag is produced between a theoretical timing of starting of the starter and the real time of starting of the starter. As a result, sometimes the engine does not start.